The present invention relates to a process and system for placing printed images, particularly printed color images, on objects having a variety of sizes and shapes.
It is known in the art to apply printed color images to various objects, including bottles, various other types of packages, writing instruments, etc., by first printing such images on release coats provided on support films, including polyester films, and then transferring the images to the final object. The processes and equipment currently employed for this purpose, typically of the offset or rotogravure type, can be operated economically only in those cases where a very large number of identical images are to be printed. This is true because very high set-up costs are associated with the creation of each image.
Typically, in the prior art, an image is separated into four basic process colors, such as cyan, magenta, yellow and black. A negative is created for each color and a photosensitive printing plate is developed for each negative. Once the four printing plates have been mounted on a press, they are inked and a press xe2x80x9cmake-readyxe2x80x9d registration process is performed. Frequently, this operation itself takes several hours. As a result, it has not been considered economically feasible to use such a process to produce fewer than 20,000 copies of the same image.
It is also known in the art to produce computer generated color images that can be transferred to objects using sublimation inks. However, these require a significant amount of time to achieve transfer. Additionally, they are only transferable to objects having surface characteristics compatible with those sublimation inks.
Further, in the prior art, the printing of rounded or arcuate objects presented special problems. In order to print on a rounded object using an apparatus such as a hot press, an arcuate die was required to surround the area of the object being printed. This meant that a new or different die was required for each object having a different circumference or curvature to their outer portion. This posed an additional expense and required that the apparatus be changed each time a different object was printed. As such, it has not been considered economically feasible to use such a process to produce a low number of printed objects.
In view of these economic limitations, when a given design, or image, is to be produced in small numbers, it is the typical practice to employ silk screening. However, silk screening requires the use of multiple screens to produce images composed of a plurality of colors and care must be taken to properly position, or register, each screen on the object to which the image is to be applied.
Problems also arise when trying to decorate objects that are formed through a molding process. Many such objects are rounded, curved or have surfaces that are otherwise difficult to decorate. Some manufacturers insert controlled release surfaces into the mold so that the articles are decorated during the molding process. However, this process requires the additional step of stripping such surfaces from the article once the casting process is complete. Further, once the decoration has been placed on the articles, it may scratch or chip off unless a further protective coating is added over the decoration.
Therefore, there is a need for a versatile printing process that may be adapted to place images on curved objects or on objects formed through a molding process.